The largest medical meeting in the world, RSNA 2007, spotlighted exciting new technologies that are advancing imaging to unprecedented levels, as well as major scientific discoveries in diagnosis and intervention of breast cancer.

Breast Health Research Highlights

Urban Women at Risk
A study by the London Breast Institution at the Princess Grace Hospital in London, UK found that women who live in urban areas have denser breasts, making them more susceptible to developing breast cancer, yet these women are less likely to go for breast screening exams than women in outlying areas. Dr. Nicholas M. Perry and colleagues analyzed digital mammograms of 972 women from urban, suburban and rural areas. They found that women living in London had significantly denser breasts than those living outside the city, and women 45 to 54 years old had twice the risk of increased density. Age specific analyses suggested that overall differences by area were more prominent in women under the age of 50. Dr. Perry said that more research needs to be done to determine the reason for this phenomenon taking into account lifestyle factors, stress, workplace and other contributors, and he cautioned all women to go for regular breast screening. He also said that women with dense breasts should be screened with digital mammography, which is more effective at detecting cancer in dense breast tissue. In concert with this study, Miriam Sklair-Levy, MD and colleagues from Hadassah Medical Center in Jerusalem looked at the influence of the Western lifestyles on breast composition. They compared breast densities of Israeli women and Ethiopian women who immigrated to Israel and found that Ethiopian born women who immigrated to Israel had significantly lower breast density than did Israeli born women. Also, past Ethiopian immigrants who adopted a Western lifestyle (fewer children, diet changes and increased hormone use) had significantly higher breast density than recent immigrants.

FDG-PET/CT in Aggressive Cancers
Another study, by researchers at the University of Texas M.D. Anderson Cancer Center in Houston is improving chances for women who are faced with inflammatory breast cancer which is aggressive and possibly lethal within six to nine months. Using fluorodeoxyglucose positron emission tomography combined with computed tomography (FDG-PET/CT), radiologists and physicists are able to spot the spread of cancer earlier. Selin Carkaci, MD, assistant professor of diagnostic radiology at MD Anderson said that PET/CT is useful in staging inflammatory breast cancer because it provides information on both the primary disease site and disease involvement throughout the rest of the body. With FDG-PET/CT, researchers can accurately determine the location of metastases early enough so that appropriate treatment can be given. The study included 41 women with an average age of 50, who were newly diagnosed with inflammatory breast cancer. Each patient underwent a whole-body FDG-PET/CT exam. Metastases were detected in 20 patients and confirmed by biopsy and supplementary imaging. Only two false positive results were made identifying those areas as cancerous when there was no disease present resulting in a 95 percent accuracy rate. The PET/CT scans also identified cancer involvement in lymph nodes with 98 percent accuracy.

Stereoscopic Digital Mammography
Results of a clinical trial at Emory University Breast Clinic in Atlanta were presented showing that stereoscopic digital mammography, a new diagnostic technique capable of producing three-dimensional, in-depth views of breast tissue, could significantly reduce the number of women who are recalled for additional tests following routine screening mammography. Stereoscopic digital mammography consists of two digital x-ray images of the breast taken at two different points of view. When viewed on a stereo display workstation, a radiologist can see the internal structure of the breast in three dimensions. In the ongoing clinical trial, researchers use a full-field digital mammography unit that is modified to take pairs of stereo images. The mammographer then fuses the stereo image pair and views the breast in depth. David J. Getty, Ph.D. division scientist at BBN Technologies of Cambridge, MA, said that stereo viewing is the only way to see the structure within the breast volume in true depth. Dr. Getty has been working on the development of the technology for over 12 years. There were 1,093 patients at elevated risk for developing breast cancer enrolled in the trial. Each received a full-field, standard digital mammography screening and a full-field, stereoscopic digital exam that were read by different radiologists. There were 259 suspicious findings detected by the combined mammography procedures and referred for further testing. Of those, 109 were diagnosed as true lesions. Standard mammography missed 40 of the 109 lesions; the stereoscopic exam failed to detect 24. Dr. Getty feels that these early results suggest that stereo digital mammography could contribute to the earlier detection of cancer.

Ethnic and Socioeconomic Considerations
Limited understanding of mammography still exists across different ethnic and socioeconomic groups, according to Nazia F. Jafri, MD, medical intern at Mount Auburn Hospital in Boston. Dr. Jafri and colleagues presented a survey at RSNA that showed that Black and Hispanic women have a different understanding of screening mammography compared to Caucasian women. The researchers surveyed 1,011 women of various educational, ethnic and socioeconomic backgrounds who underwent screening mammography at Boston University Medical Center. The survey asked women questions about their understanding of mammography and their preferences regarding callback after a suspicious finding. Nearly one-third of Black and Hispanic women thought mammography would detect more cancers than it actually does. According to the United States Department of Health and Human Services, African-American women between the ages of 35 and 44 have a breast cancer death rate more than double the rate for Caucasian women in the same age group, even though breast cancer incidence tends to be lower among minority women than among Caucasian women. And, Hispanic women in the United States are 20 percent more likely to be diagnosed with late-stage breast cancer than Caucasian women. The researchers tried to determine if ethnicity or socioeconomic background made a difference in women's beliefs or opinions regarding breast cancer screening and early detection. One of the conclusions was that limited increased community outreach and education targeted at minority and underserved women may lead to better breast cancer prognoses in these groups.


Breast Imaging Equipment Vendors Show Their Wares

More than 700 commercial companies showed off their state-of-the-art equipment at RSNA and breast imaging was a dominant application. (Nine companies showed breast biopsy tables alone.) The following is a synopsis of selected relevant exhibitors.

Confirma
Confirma announced that a study by the Seattle Cancer Care Alliance and the University of Washington presented at RSNA suggests that the CADstream system's patented "worst curve" algorithm for analyzing kinetics may assist in determining malignancy. The study, led by Dr. Lilian Wang, focused on the evaluation of kinetics and found that the most suspicious curve as identified by CADstream was significantly different between benign and malignant lesions. This supports the recommendation of the American College of Radiology's Breast Imaging Reporting and Database System (BI-RADS®) Atlas for breast MRI to report the "worst looking" curve. The study found that any washout enhancement was associated with malignancy in nearly half of lesions. Dr. Wang's study is "MRI Detected Suspicious Breast Findings: Comparison of Kinetic Features Measured by Computer-aided Evaluation in Benign and Malignant Lesions."

Confirma develops and markets application-specific CAD systems and accessories for magnetic resonance imaging studies (MRI). CADstream is the standard in CAD for MRI, with more than 800 installations and 2,500 users worldwide. The CADstream system automates analysis, reporting and interventional planning of studies and promotes standardization with the incorporation of BI-RADS, which guides the breast cancer diagnostic routine and decision-making process.

AIT
Advanced Imaging Technologies, (AIT) Richland, WA featured the ARIA Breast Imaging System which combines mammography and conventional ultrasound for detecting solid masses. The approach provides the ability to image dense breast tissue effectively, regardless of age or ethnicity, with results that correlate well to actual pathology. Superior needle definition provides greater accuracy for image-guided biopsy. The system also features 3D rendering and lesion segmentation with contrast attenuation comparison, retrieval of prior comparative studies for quick cross correlation with known landmarks for yearly comparison, and seamless integration into the patient workflow.

Hologic
Hologic, Bedford, MA had its Selenia Suite on display. The Selenia is used for digital mammography with direct capture technology that delivers clear, detailed images to support radiologists in the early detection of breast cancer. The SecurView workstations allow radiologists to review and interpret images with total interactive ease. Images and annotations flow freely between the technologist and radiologist, improving workflow and patient throughput. R2 DigitalNow™ allows mammography departments to digitize prior studies and archive to PACS for use in a soft-copy viewing environment. MammoPad, a soft warm breast cushion used during a mammogram, relaxes the patient allowing for optimal positioning without compromising the high level of image quality.

Imaging Diagnostic Systems
Imaging Diagnostic Systems, Plantation, FL featured the CT Laser Mammography (CTLM®) system, a breast imaging system that does not require breast compression or exposure to radiation. Patients lie face down on a scanning bed so that the breast is naturally suspended in the scanning chamber. The chamber itself contains a laser and multiple electronic signal detectors. As the laser rotates around the breast, the detectors collect absorption information in cross-sections, as in a CT exam. Physicians may view CTLM images in individual slices, or as 3-D volume images of the entire breast. CTLM is designed to be used in conjunction with mammography. It reveals information about blood distribution in the breast and may visualize the process of angiogenesis, which usually accompanies tumor growth.

Siemens
Siemens Medical Solutions, Malvern, PA introduced MAMMOMAT Novation S, a cost-effective solution for facilities that are making the transition to digital breast imaging but don't require the advanced functionality of state-of-the art systems. The MAMMOMAT Novation S optimizes workflow, utilizes the latest full-field amorphous Selenium (aSe) detectors and features Tungsten/Rhodium (W/Rh) X-ray technology, which reduces the dose. Siemens also featured breakthrough breast ultrasound technology with eSie Touch™ elasticity imaging that has shown promise in reducing reliance on invasive breast biopsy procedures. And, Siemens' solution for quantitative breast MRI breast spectroscopy, syngo® GRACE, allows physicians to obtain essential metabolic information about the biochemical composition of breast lesions. This additional information helps physicians better distinguish between malignant and benign lesions to potentially reduce unnecessary breast biopsies.

Siemens offers a full portfolio of technologies combining advanced imaging, laboratory diagnostics, and information technologies to address breast health, in a multimodality approach including ultrasound, magnetic resonance imaging (MRI), and extending to digital mammography systems and immunodiagnostic testing and molecular imaging of masses found in the breast.

Z-Tech
Z-Tech Medical, Inc. of Westford, MA has developed a new technology for the early detection of breast cancer. The Azura BreastScan™ System is based on homologous electrical difference analysis and measures physiologic differences between healthy and abnormal breast tissue.

NVIDIA
NVIDIA Corporation and Planar Systems are cooperating closely to produce display systems that will enable doctors to more effectively screen for breast cancer. The two companies are working to develop high-contrast, 10-bit grayscale display systems for use in mammography and other medical applications.

Currently, digital mammography displays that rely on standard PC workstations are limited to 8-bit grayscale, which provides only 256 possible shades of gray for each pixel. Being limited to 256 shades of gray can sometimes obscure valuable data when an image is displayed; mammography systems and other medical sensors, however, are capable of greater degrees of contrast.

Instead of developing specialty hardware, NVIDIA and Planar have developed a method of "pixel packing" that allows 10-bit or 12-bit grayscale data to be transmitted from an NVIDIA Quadro® graphics board to a Planar Dome display using a standard DVI cable. Instead of three 8-bit grayscale channels, now two 10- or 12-bit channels are transmitted, providing up to 864 possible shades of gray at more than three times the image contrast of an 8-bit system.

No specialty hardware is required. The close cooperation between NVIDIA and Planar has produced something almost unique in the field of medical technology--superior imaging technology that uses industry-standard hardware. Soon, without a lot of increased costs, radiologists will be able to use these 10-bit display systems to screen for breast cancer more efficiently and with greater confidence.